Stainless Works 1985-91 L98 C4 Corvette Headers. These headers feature 1 5/8" primary tubes, a 3/8" thick flange to prevent warping, 2 1/2" slip joint collector, and include 2 1/2" y-pipe. Includes AIR tubes and O2 bungs. 2 1/2" diameter y-pipe fits to factory exhaust.